In a common rail fuel injection system, the injection pressure can be produced independently of the engine speed and the injection quantity. The decoupling of pressure production and injection is accomplished by means of a pressure reservoir (rail). To produce the pressure, a high-pressure pump (HDP) is provided, which delivers the fuel into the pressure reservoir. The high-pressure pump can be connected to a tank by a fuel inlet duct and to the pressure reservoir by a fuel outlet duct. The high-pressure pump compresses the fuel fed in from the fuel inlet duct and, in a pump working space, produces a high-pressure volume of the fuel, which is discharged to the pressure reservoir. In the injection of fuel into a cylinder, an injection volume of the fuel is taken from the pressure reservoir.
An inlet valve is arranged ahead of the high-pressure pump in the fuel inlet duct. An outlet valve is provided after the high-pressure pump in the fuel outlet duct. In addition to passive valves, which open and close in accordance with a pressure, the inlet and outlet valve can each be configured as an active valve. The purpose of conventional active valves is to control the volume flow which is actually available for the production of high pressure in such a way that neither an excess nor a lack of high-pressure volume flow arises. The volume flow at the high-pressure outlet of the high-pressure pump exhibits oscillations dependent on the stroke frequency, depending on the delivery properties of a piston pump. Moreover, the periodic opening and closure of the inlet valve leads to noise, the frequency of which is a function of the speed of a drive shaft of the high-pressure pump.